streamclone: define first iteration of version 2 of stream format
(This patch is based on a first draft from Gregory Szorc, with deeper rework)
Version 1 of the stream clone format was invented many years ago and suffers
from a few deficiencies:
1) Filenames are stored in store-encoded (on filesystem) form rather than in
their internal form. This makes future compatibility with new store
filename encodings more difficult.
2) File entry "headers" consist of a newline of the file name followed by the
string file size. Converting strings to integers is avoidable overhead. We
can't store filenames with newlines (manifests have this limitation as
well, so it isn't a major concern). But the big concern here is the
necessity for readline(). Scanning for newlines means reading ahead and
that means extra buffer allocations and slicing (in Python) and this makes
performance suffer.
3) Filenames aren't compressed optimally. Filenames should be compressed well
since there is a lot of repeated data. However, since they are scattered
all over the stream (with revlog data in between), they typically fall
outside the window size of the compressor and don't compress.
4) It can only exchange stored based content, being able to exchange caches
too would be nice.
5) It is limited to a stream-based protocol and isn't suitable for an on-disk
format for general repository reading because the offset of individual file
entries requires scanning the entire file to find file records.
As part of enabling streaming clones to work in bundle2, #2 proved to have a
significant negative impact on performance. Since bundle2 provides the
opportunity to start fresh, Gregory Szorc figured he would take the
opportunity to invent a new streaming clone data format.
The new format devised in this series addresses #1, #2, and #4. It punts on #3
because it was complex without yielding a significant gain and on #5 because
devising a new store format that "packs" multiple revlogs into a single
"packed revlog" is massive scope bloat. However, this v2 format might be
suitable for streaming into a "packed revlog" with minimal processing. If it
works, great. If not, we can always invent stream format when it is needed.
This patch only introduces the bases of the format. We'll get it usable through
bundle2 first, then we'll extend the format in future patches to bring it to its
full potential (especially #4).
#require killdaemons
$ cat > writelines.py <<EOF
> import sys
> path = sys.argv[1]
> args = sys.argv[2:]
> assert (len(args) % 2) == 0
>
> f = file(path, 'wb')
> for i in xrange(len(args)/2):
> count, s = args[2*i:2*i+2]
> count = int(count)
> s = s.decode('string_escape')
> f.write(s*count)
> f.close()
>
> EOF
> cat <<EOF >> $HGRCPATH
> [extensions]
> mq =
> [diff]
> git = 1
> EOF
$ hg init repo
$ cd repo
qimport without file or revision
$ hg qimport
abort: no files or revisions specified
[255]
qimport non-existing-file
$ hg qimport non-existing-file
abort: unable to read file non-existing-file
[255]
qimport null revision
$ hg qimport -r null
abort: revision -1 is not mutable
(see 'hg help phases' for details)
[255]
$ hg qseries
import email
$ hg qimport --push -n email - <<EOF
> From: Username in email <test@example.net>
> Subject: [PATCH] Message in email
> Date: Fri, 02 Jan 1970 00:00:00 +0000
>
> Text before patch.
>
> # HG changeset patch
> # User Username in patch <test@example.net>
> # Date 0 0
> # Node ID 1a706973a7d84cb549823634a821d9bdf21c6220
> # Parent 0000000000000000000000000000000000000000
> First line of commit message.
>
> More text in commit message.
> --- confuse the diff detection
>
> diff --git a/x b/x
> new file mode 100644
> --- /dev/null
> +++ b/x
> @@ -0,0 +1,1 @@
> +new file
> Text after patch.
>
> EOF
adding email to series file
applying email
now at: email
hg tip -v
$ hg tip -v
changeset: 0:1a706973a7d8
tag: email
tag: qbase
tag: qtip
tag: tip
user: Username in patch <test@example.net>
date: Thu Jan 01 00:00:00 1970 +0000
files: x
description:
First line of commit message.
More text in commit message.
$ hg qpop
popping email
patch queue now empty
$ hg qdelete email
import URL
$ echo foo >> foo
$ hg add foo
$ hg diff > url.diff
$ hg revert --no-backup foo
$ rm foo
Under unix: file:///foobar/blah
Under windows: file:///c:/foobar/blah
$ patchurl=`pwd | tr '\\\\' /`/url.diff
$ expr "$patchurl" : "\/" > /dev/null || patchurl="/$patchurl"
$ hg qimport file://"$patchurl"
adding url.diff to series file
$ rm url.diff
$ hg qun
url.diff
import patch that already exists
$ echo foo2 >> foo
$ hg add foo
$ hg diff > ../url.diff
$ hg revert --no-backup foo
$ rm foo
$ hg qimport ../url.diff
abort: patch "url.diff" already exists
[255]
$ hg qpush
applying url.diff
now at: url.diff
$ cat foo
foo
$ hg qpop
popping url.diff
patch queue now empty
qimport -f
$ hg qimport -f ../url.diff
adding url.diff to series file
$ hg qpush
applying url.diff
now at: url.diff
$ cat foo
foo2
$ hg qpop
popping url.diff
patch queue now empty
build diff with CRLF
$ $PYTHON ../writelines.py b 5 'a\n' 5 'a\r\n'
$ hg ci -Am addb
adding b
$ $PYTHON ../writelines.py b 2 'a\n' 10 'b\n' 2 'a\r\n'
$ hg diff > b.diff
$ hg up -C
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
qimport CRLF diff
$ hg qimport b.diff
adding b.diff to series file
$ hg qpush
applying b.diff
now at: b.diff
try to import --push
$ cat > appendfoo.diff <<EOF
> append foo
>
> diff -r 07f494440405 -r 261500830e46 baz
> --- /dev/null Thu Jan 01 00:00:00 1970 +0000
> +++ b/baz Thu Jan 01 00:00:00 1970 +0000
> @@ -0,0 +1,1 @@
> +foo
> EOF
$ cat > appendbar.diff <<EOF
> append bar
>
> diff -r 07f494440405 -r 261500830e46 baz
> --- a/baz Thu Jan 01 00:00:00 1970 +0000
> +++ b/baz Thu Jan 01 00:00:00 1970 +0000
> @@ -1,1 +1,2 @@
> foo
> +bar
> EOF
$ hg qimport --push appendfoo.diff appendbar.diff
adding appendfoo.diff to series file
adding appendbar.diff to series file
applying appendfoo.diff
applying appendbar.diff
now at: appendbar.diff
$ hg qfin -a
patch b.diff finalized without changeset message
$ touch .hg/patches/append_foo
$ hg qimport -r 'p1(.)::'
$ hg qapplied
append_foo__1
append_bar
$ hg qfin -a
$ rm .hg/patches/append_foo
$ hg qimport -r 'p1(.)::' -P
$ hg qpop -a
popping append_bar
popping append_foo
patch queue now empty
$ hg qdel append_foo
$ hg qdel -k append_bar
qimport -e
$ hg qimport -e append_bar
adding append_bar to series file
$ hg qdel -k append_bar
qimport -e --name newname oldexisitingpatch
$ hg qimport -e --name this-name-is-better append_bar
renaming append_bar to this-name-is-better
adding this-name-is-better to series file
$ hg qser
this-name-is-better
url.diff
qimport -e --name without --force
$ cp .hg/patches/this-name-is-better .hg/patches/3.diff
$ hg qimport -e --name this-name-is-better 3.diff
abort: patch "this-name-is-better" already exists
[255]
$ hg qser
this-name-is-better
url.diff
qimport -e --name with --force
$ hg qimport --force -e --name this-name-is-better 3.diff
renaming 3.diff to this-name-is-better
adding this-name-is-better to series file
$ hg qser
this-name-is-better
url.diff
import patch of bad filename
$ touch '../ bad.diff'
$ hg qimport '../ bad.diff'
abort: patch name cannot begin or end with whitespace
[255]
$ touch '.hg/patches/ bad.diff'
$ hg qimport -e ' bad.diff'
abort: patch name cannot begin or end with whitespace
[255]
qimport with bad name, should abort before reading file
$ hg qimport non-existent-file --name .hg
abort: patch name cannot begin with ".hg"
[255]
$ hg qimport non-existent-file --name ' foo'
abort: patch name cannot begin or end with whitespace
[255]
$ hg qimport non-existent-file --name 'foo '
abort: patch name cannot begin or end with whitespace
[255]
qimport http:// patch with leading slashes in url
set up hgweb
$ cd ..
$ hg init served
$ cd served
$ echo a > a
$ hg ci -Am patch
adding a
$ hg serve -p $HGPORT -d --pid-file=hg.pid -A access.log -E errors.log
$ cat hg.pid >> $DAEMON_PIDS
$ cd ../repo
$ hg qimport http://localhost:$HGPORT/raw-rev/0///
adding 0 to series file
check qimport phase:
$ hg -q qpush
now at: 0
$ hg phase qparent
1: draft
$ hg qimport -r qparent
$ hg phase qbase
1: draft
$ hg qfinish qbase
$ echo '[mq]' >> $HGRCPATH
$ echo 'secret=true' >> $HGRCPATH
$ hg qimport -r qparent
$ hg phase qbase
1: secret
$ cd ..
$ killdaemons.py
check patch name generation for non-alpha-numeric summary line
$ cd repo
$ hg qpop -a -q
patch queue now empty
$ hg qseries -v
0 U imported_patch_b_diff
1 U 0
2 U this-name-is-better
3 U url.diff
$ echo bb >> b
$ hg commit -m '==++--=='
$ hg qimport -r tip
$ hg qseries -v
0 A 1.diff
1 U imported_patch_b_diff
2 U 0
3 U this-name-is-better
4 U url.diff
check reserved patch names
$ hg qpop -qa
patch queue now empty
$ echo >> b
$ hg commit -m 'status'
$ echo >> b
$ hg commit -m '.'
$ echo >> b
$ hg commit -m 'taken'
$ mkdir .hg/patches/taken
$ touch .hg/patches/taken__1
$ hg qimport -r -3::
$ hg qap
1.diff__1
2.diff
taken__2
check very long patch name
$ hg qpop -qa
patch queue now empty
$ echo >> b
$ hg commit -m 'abcdefghi pqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghi pqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghi pqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghi pqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghi pqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghi pqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ'
$ hg qimport -r .
$ hg qap
abcdefghi_pqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghi_pqrstuvwxyzabcdefg